The British government estimates that 200,000 people a day are being infected with the latest coronavirus variant, omicron.

Yet in Parliament on Tuesday, a record number of Conservative lawmakers voted against one of Prime Minister Boris Johnson’s key measures to quell the outbreak — a policy of vaccine certification to enter nightclubs and places where large crowds have gathered.

The policy passed, with the help of votes from the opposition, as did several other related COVID-19 measures. But with nearly 100 Conservatives voting against Johnson, it was a stinging rebuke of their leader, undermining his authority at a time when he has called for a national campaign to prevent omicron from swamping the country.